I have been playing around with caustics and sort of got sidetracked by a glass of wine :rolleyes:

Now wine in a glass is something i have been itching to learn how to do..properly. I just can't get past that sad beginners look

here is my attempt so far

http://www.black-and-white-to-color.com/stuff/wineglass.jpg

Now the caustics are really bad but what i would like to learn is how to light and texture this scene so the wine look really belivable. I enclose a scene file for you all to chortle at my befuddled attempts !!

http://www.black-and-white-to-color.com/stuff/wineglass.zip

The glass is very roughly modelled from a lathed spline and then i copied to upper portion and sized it down for the wine

I have tried GI and all combinations of relectivity and transparency but just can't get the look right

Does anyone know how to get that perfect glass of wine ? Burgundy, Rose, Beaujolais..not too bothered !!

benytone

12-05-2005, 02:08 AM

two work from me with caustics.
caustics depends on glas and contents of the glas.

These al look good especially bobtronics..very rose..however i think there is something missing from the body of the wine, that elusive translucent look with some warm luminosity

Perhaps beter seen in a burgundy, or rioja

Neil V

12-05-2005, 08:35 AM

I'll take a look at this later on - I love a challenge. Benytones work is nice but he definitely needs to increase the amount of samples. At the moment the caustics look as if they're lights emenating from a silver disco ball.

Neil V

Mono Jojoy

12-05-2005, 11:09 AM

These al look good especially bobtronics..very rose..however i think there is something missing from the body of the wine, Maybe you mean the sugar and glycol content of some wines ;) maybe thats whats missing ;)

nutriman

12-05-2005, 03:45 PM

@ paulselhi: A shadow would add some realism to it, then check the refractive index for glass (somewhere around 1.5) and wine (i am not that much of a wine conaisseur..)

a little bit of translucency could be looking good on the wine.

also try a photostudio lighting to achieve some slick results.

I'll try to have something uploaded when I'm back home.

ThePriest

12-05-2005, 05:14 PM

The Caustics seemed to have limited themselves to the glass only in my attempt
and the wine looks more like cheap sherry than anything else.

moka.studio

12-05-2005, 05:22 PM

The Caustics seemed to have limited themselves to the glass only in my attempt
and the wine looks more like cheap sherry than anything else.

I think the color of the wine is too constant, it looks therefore too thick, more like syrup.

cornel

12-05-2005, 05:50 PM

For those of you owning translucent-pro: use it !

Have to love the vreel 'transparent' shader which is included in the package.
...still the best approach for color-absorption of liquids, unreached since R8 came out.
Thanks to Arndt :-)

actually, itīs more than old...
wondering why there isnīt still anything similar in R-9.5 or fR-shadertree.
Since years, Arndt shows status-quo with this rarely used (and known) shader.

but... aware of the rendertimes !!!

Per-Anders

12-05-2005, 07:21 PM

there's plenty in the fr shader tree. try the raytrace node for this sort of effect. or you could even if you wanted use the fast skin shader. or you can make your own using the raylength and a gradient and a mask based on internal ior rays.

Bob3D

12-05-2005, 08:23 PM

Here's an effort of mine from ages ago. It's not wine, but fruit juice, but I think the glass looks okay.

Granted I'm a total noob w/ C4D. But, I aint exactly blown away by C4D glass. I mean, c'mon, even the HDRI pics are sub-par.

Not saying that C4D cant do good glass. But, there's been at least 5 threads about how hard it is to do. There was one comparing C4D arch glass to MW glass, then there was another one trying to get a decent agreed upon material setting for glass (included translucent pro, sla shaders, and even image maps). None these threads came away with a glass that looks like glass in C4D.

Why is it so hard to do glass in C4D? Glass isnt a foreign phenomenon, its pretty standard. Yes, Standard! So, the standard C4D renderer should be able to produce it. No plugin, No AR.

um glass is hard? it's a lot easier in c4d than it is in any other app i've tried.

seems pretty easy to me, just turn on transparency turn on fresnel, dial up a suitable ior, turn off color, apply something decent to reflect/refract light and render...

LucentDreams

12-05-2005, 10:43 PM

well that tutorial is the same cheat msot render artists have been using for ages (I believe hanine even covers this in the 3D fluff DVD doesnt she?)

its a matter of removing the inside half of the glass from the refraction.

Cinema lacks the ability to have a changin IOR, but thats the only limitation at all and IV"e seen several realistic glasses.

one must also consider the experience of the users posting when considering the quality of their renders. If they've never tried doign glass their image is going to be of a lower quality then someone whose done glass several times.

Per-Anders

12-05-2005, 11:17 PM

absolutely right Kai, however, i still say that making decent glass in cinema is a lot easier than elsewhere. however the main thing bout glass isn't so much the material itself, as the environment it's in (i know i've said this before lots of times and there's gotta be enough peopel bored of me saying it but...), glass is a reactive material, refractive/reflective materials need things to refract/reflect to get the best results. and that's something that in the end always takes much longer than the object itself.

It's like you have to imagine you're a photographer setting up the scene. Putting everything into place. A profesional photographer will pay a lot of care and attention to the setup, and it's really not that easy, every time i try and make a new scene orimage I learn a little bit more, and I can see a whole long road ahead of me before i get good at this stuff.

Anyhow i thought i'd quickly knock up a little c4d glass that should hopefully show that the possibility is there (though for some reason i had ao on the floor here and i didn't turn on the transparency option in it, so the bottom of hte glass is kinda dark :D, ah well, so uh... just pretend this vase has one of those felt things on the bottom ok? :P)

http://www.peranders.com/general/cineglass01.jpg

benytone

12-06-2005, 12:58 AM

example of me

http://pixerve.de/29458/chocoo.html

http://pixerve.de/29454/choco.html

maybe Vray is good, but i love AR.

.

paulselhi

12-06-2005, 01:47 AM

The translucent pro seems to make good wine, if you have the wine object as as seperate render you get some good "full bodied" wine

It also look reasonable in a glass from above but the problem comes in a side on top/side view, it seems that the real problem is refraction/fresnel.transparency

Yes you need the glass to have realistic refraction but in doin so you will distort the representaion of the wine object

I notice an exclusion setting in the compositing tag..can this be somehow used to have the glass refract the surroundings but not the wine object that it will contain ?

ThirdEye

12-06-2005, 02:14 AM

Cinema lacks the ability to have a changin IOR, but thats the only limitation at all and IV"e seen several realistic glasses.

i wish we had a refraction channel, sigh

ThirdEye

12-06-2005, 02:37 AM

ok here's a fast tutorial for a wine glass like the following one (this is a photo i dloaded off of google images, some good references are the first thing you gotta check)

1) your model has to be accurate, otherwise it'll never work. 90% of the flutes i've seen in this thread have a flat bottom (the part on the ground), which doesn't help at all, that's not the shape of a real one, check it on a real flute. Usually the best way to model a flute is a Lathe NURBS object with a spline in it

2) the material: as Per said you need to use an accurate ior (1.5 to 1.9 depending on the glass type ie its thickness). I usually leave the fresnel checkbox active but bring down the fresnel reflectivity value, i prefer using the reflections channel instead. Switch the colour off, switch the material to blinn if you wanna use speculars, otherwise just use reflections with the fresnel shader

WINE:

1) reuse the same spline you've used for the glass and remove the useless points, then throw it into another Lathe NURBS object

2) the material: you can even copy/paste the glass material, change its ior (this is heavily dependent on the kind of liquid/effect you wanna get) and, as suggested, use the Translucent shader by Arndt Von Koenigsmarck. NOW THE DISPLACEMENT TRICK: look at the image above, and if you can't see it clearly just grab a real glass and put some coloured liquid in it: you should notice the wine seems going INTO the glass surface it touches, that's an effect of the refraction. To get it (and also to get rid of the overlapping problem of the glass/wine splines) put a simple solid colour shader (set it to white) into the displacement channel (you don't need spd of course), lower the % and, depending on the size of your object play a bit with the displacement height, a few mm should be enough.

RENDERING:

as Per said the environment is the most important part of the whole excercise: you can use a HDRI (avoid Debevec's, they're too blurry and small for this purpose, the best ones are Sachform HDRI's imo), you can build a studio setup with white cards, you can really go wild with this, just remember you need bright and sharp white reflections. Some glow wher e the reflections are strong doesn't hurt for sure, same about a veeery subtle bump, glass is almost never 100% smooth. GI is pretty useless for a transparent material, i would go for Ambient Occlusion or just traditional lighting. Caustics are the LAST thing you should add (if you wanna add them of course), remember that spotlights are the only light source you should use for caustics, otherwise you'll get a ton of artifacts and biblical rendertimes to get rid of them.

Feel free to go wild with Photoshop for postwork of course ;)

That's basically it, i hope this helps.

EDIT: something i forgot, you'll need to add a normal direction shader in the specular /reflections channels to get rid of the internal reflections effect, otherwise your object will look like a bubble (ie not solid enough)

JoelOtron

12-06-2005, 02:52 AM

Awesome glass mdmesadie--I'd drink out of it.
A thing to think about with wine (or any liquid in a glass) is that the surface tension causes the liquid to form a lip along the edge. So the wine curves up and almost goes flush with the glass. This subtle detail might help (often missing from most renders I see)

(edit--3rdeye got it.)

My humble 10 minute attempt
(Its a magic floating glass)

http://www.betatronstudios.com/testdec/Picture%2019.jpg

MJV

12-06-2005, 02:53 AM

Here are a few of mine:

http://www.mvpny.com/3DStills/slides/Glass.jpg

http://www.mvpny.com/3DStills/slides/GlassCaustic.jpg

http://www.mvpny.com/GlassOfMilk17.jpg

MJV

12-06-2005, 02:58 AM

For me, the biggest thing missing in the glass realism department is a way to set glass' shadow transparency independently of its visual transparency.

Per-Anders

12-06-2005, 05:12 AM

thats' easily possible, just make a seperate shadow caster light linked to your glass object and set it's shadow density higher or lower (as you need it) than the default 100%.

Really could use the color bleed thingy in Arndt's Translucent pro plugin. I cant get that effect using the old Banji shader--which is what I used for the wine and the glass.
The liquid should become almost colorless as it approaches the top surface.

Thanks Thirdeye for some good pointers.

JoelOtron

12-06-2005, 06:17 AM

I wasnt done, I guess.

Having trouble getting the caustics --especially the volume of the wine to come through in the floor shadow.

http://www.betatronstudios.com/testdec/Picture%2024.jpg

http://www.betatronstudios.com/testdec/Picture%2026.jpg

paulselhi

12-06-2005, 07:04 AM

Great work everyone, MJV your glasses are incredible and Joel your render is superb..

This as far as i have got using the translucent shader, I think i am on my way to getting that rich red wine look but i am having problems with my mats in general. remember i am a real muppet when it comes to texturing ( err. and modelling..animation...)

http://www.black-and-white-to-color.com/stuff/wineglass2.jpg

What i did was do a real basic glass model just for test purposes, it has the top extruded down to give thickness, now i have to have my glass shader set to front only (see the file included) otherwise i get a massive band of bloom/reflection in the middle of the glass. I just can't get my head around all this damn refraction/fresnel stuff

It would be great if someone could have a look at the file and tell me what the issue is, i suspect it may have to do with the fact that there are 2 levels of polygons on the glass bowl, the inner and the outer and as both of these have the same mat this must cause issues with refraction/transparency etc

Here is the file ( using translucent pro)

http://www.black-and-white-to-color.com/stuff/wineglass3.zip

moka.studio

12-06-2005, 08:04 AM

http://www.peranders.com/general/cineglass01.jpg

Per, this one is really nice!
(like the look of the image in general, which also helps)

MJV, very nice glass exemples,
Joel, Also quite nice, the color is still a bit off though.
Paul, nice, the ripple on the last one is too strong, but the deep color is quite good - the fade from the lighter color takes too long somehow, so that it looks a bit waxy, but the overall color is getting closest to a read wine IMO.

3rdEye, good input, - yours does not look too bad either ;)

jondoe0ne

12-06-2005, 10:10 AM

@moka-j: " 3rdEye, good input, - yours does not look too bad either" i think his is a real one, googled over the internet... -> "ok here's a fast tutorial for a wine glass like the following one (this is a photo i dloaded off of google images..."

moka.studio

12-06-2005, 10:27 AM

@moka-j: " 3rdEye, good input, - yours does not look too bad either" i think his is a real one, googled over the internet... -> "ok here's a fast tutorial for a wine glass like the following one (this is a photo i dloaded off of google images..."

I know ... hence the wink -> ;)

paulselhi

12-06-2005, 10:52 AM

Almost there..now to see if the mat plays well with realflow meshes

http://www.black-and-white-to-color.com/stuff/wineglass4.jpg

moka.studio

12-06-2005, 10:55 AM

Hi Paul,
I think the color look watered down this time, I really liked the deep burgundy that you had previously

paulselhi

12-06-2005, 11:16 AM

yes it has gone a bit rose, i will have to find a happy medium between the 2

nutriman

12-07-2005, 12:02 AM

sorry, got a little later..

http://www.realiez.de/3dpix/wineglass.jpg
caustics are tiny.. :D but i like the rest.
I was too unpatient to use area shadows and a better AA on the glass.

MJV: that is really beautiful!

jondoe0ne

12-08-2005, 12:19 AM

no... i am late
no other scene optimization than putting my materials and lowering the caustics settings you have set because of my ancient athlon xp 2600+ and 3x256 ram. render times ~13 min. more or less...

paulselhi

12-08-2005, 09:46 AM

Nutriman and Jon those are great renders are you both using the translucent shader ?

jondoe0ne

12-08-2005, 10:00 AM

no i haven't used it... just a plain environment channel in the dark one, and fresnel enabled in the environment channel in the rose one... i have poste only the materials, which you can replace in your scene. the wine mat is with the fresnel enabled in the env channel, if you disable it you'll get the dark burgundy wine...

nutriman

12-08-2005, 09:41 PM

Me neither, I was playing with some sss settings but ended up with not using it.
Thank you btw.
Here's the file:
http://www.realiez.de/szenen/wineglass.zip

soapy

12-28-2005, 05:59 AM

FYI, you may want to set up the refraction correctly, when refraction has equal parameters in the glass and liquid you get a bad edge as seen here:http://www.renderosity.com/photos/MSG2/Message2267710.jpg

soapy

12-28-2005, 06:05 AM

To fix it, make the refraction numbers slightly different between glass and liquid and you will get the result as seen here, notice the edge is more realistic, you don't see the thickness of the glass at the edges of the whiskey:http://www.renderosity.com/photos/MSG2/Message2268855.jpg

Incarnadine

01-03-2006, 05:24 PM

Thanks for that pointer!

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